[R-sig-Geo] simplify a polygon window

[Barry Rowlingson]

On Thu, Oct 4, 2012 at 1:26 PM, sara martino <saramartino at yahoo.com> wrote:
> Hi,
>
> I am working with a point pattern whose window is a spatial polygon which describe the cost of Norway.
>
> I need to get a smoother version of such polygon which wraps the original one.

You mean 'coast' of Norway? You want to undo all Slartibartfast's good
work? He won an award for that!

http://en.wikipedia.org/wiki/Slartibartfast

> I have tried to use the function
>
>> simplify.owin(my.owin,80000)
> but this does not work since some parts of the original polygon will lay outside the simplified one.
>
> Does anyone know how to do that?

 You could use the buffering functions in rgeos to expand the area
slightly - but that might end up making the polygon more complex
again.

 You could possibly also use an alpha-shape instead of whatever
polygon you have:

http://procomun.wordpress.com/2011/04/07/alpha-shapes-with-lattice/

 but at that point you are probably throwing away the concept that the
polygon is the window in which your process occurs. In which case your
analysis becomes problematic.

 Are you losing points after the simplification? You could just drop them.